JPH0584933A - Line printer - Google Patents

Abstract

PURPOSE:To constitute the title printer so that driving is made possible by a small-capacity power source and driving control of a line head where printing speed also is not lowered extremely can be performed, by a method wherein a block which is tuned ON in one time according to a number of dots within one line is decided. CONSTITUTION:The title line printer is constituted so that a key board 102 selects a desired letter and a signal is sent to a CPU101 by pushing a punching key. A driver 105 is constituted so that it turns ON dots each of a thermal head 7 according to the signal for from the CPU101. The driving power source 106 is constituted so that electric power necessary to turn ON dots each of the thermal head 7 is supplied to the driver 105 and sixty four dots out of the total number of dots of the thermal head 7 can be turned ON at the same time by its maximum supply electric power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line printer.

[0002]

2. Description of the Related Art Conventionally, in the control of a line head in which a large number of dots are arranged in a line, if one line is turned on at a time, a considerably large current will flow when all dots are turned on, and a large capacity is required for the power supply. Becomes Therefore, one line is divided into 2 to 3 blocks, and 1 is divided by time division.
It was turned on for each block. FIG. 9 shows one line 768.
It is a character pattern in which dots are divided into two blocks. The feed direction is from left to right. In FIG.
Since there is no dot to be turned on in the A column, the block is not turned on. On the B row, blocks a and b are turned on once. It does not turn on on column C. Block a on column D,
b is turned on once. In this case, about 100 dots are simultaneously turned on in block a.

[0003]

However, even in one divided block, when all the dots are on in the block, a considerably large current flows. Therefore, a power supply that can continuously supply that much current is required. In the case of FIG. 9, a power supply for turning on a maximum of 384 dots at the same time is required. Even if there are only a few dots to be turned on in one block, it is necessary to turn on the blocks a and b once, that is, twice.

The present invention has been made in order to solve the above-mentioned problems, and makes it possible to drive with a small-capacity power supply by determining the blocks to be turned on at one time according to the number of dots in one line. The purpose is to realize the drive control of the line head in which the printing speed does not drop extremely.

[0005]

In order to achieve this object, a line printer of the present invention is, as shown in FIG. 1, a line head means for forming an image on a print medium and one of the line head means. A driving power supply that can supply power enough to turn on a smaller number of dots than the total number of dots on a line and the number of dots that are turned on within one line of the line head means are counted, and the count number can supply the maximum driving power. A control means is provided for turning on the dots of which number is equal to or less than the number of dots for which the count is completed when the value becomes larger than a predetermined value determined according to the electric power.

The control means counts the number of dots turned on for each preset block, and when the counted number becomes larger than a preset value smaller than the total number of one line of the line head means, You may make it turn on the block for which the count of the dots turned on before that is completed.

[0007]

In the line printer of the present invention having the above-mentioned structure, the driving power supply supplies electric power enough to turn on a number of dots smaller than the total number of dots of one line of the line head means, and the control means of the line head means. The number of dots that are turned on in one line is counted, and when the counted number becomes larger than a predetermined value determined according to the maximum power that can be supplied by the driving power source, the dots whose number is equal to or less than the number of dots that have finished counting are selected. When turned on, the line head means forms an image on the print medium.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a perspective view of the printer of this embodiment, and FIG. 3 is a sectional view of the printer of this embodiment. In FIG. 2, a heat-sensitive stencil sheet (hereinafter abbreviated as a stencil sheet) 1 is wound around both ends of an original winding roll 3 and a winding roll 5, respectively.

Then, the base paper 1 pulled out from the original winding roll 3 is conveyed between the image forming thermal head 7 and the platen 9 arranged on the right side of the original winding roll 3, and further the original winding side guide roll 15, It is wound by the winding roll 5 via the winding side guide roll 19.

Both the original winding side guide roller 15 and the take-up side guide roller 19 are formed with rims corresponding to the width of the base paper 1 at both ends, and guide the base paper 1 so that it does not meander during conveyance. Further, an ink pad 32 is arranged between the original winding side guide roll 15 and the winding side guide roll 19 so that the ink application surface is in contact.

As shown in FIG. 4, the base paper 1 is composed of a thermoplastic film 21, an adhesive layer 23, and a porous support 25. The thermoplastic film 21 and the porous support 25 are different from each other. It is adhered by the adhesive layer 23. In this embodiment, the thermoplastic film 21 is a polyethylene terephthalate film (hereinafter abbreviated as PET film) having a thickness of 2 μ, but other examples thereof include films of polypropylene, vinylidene chloride-vinyl chloride copolymer, and the like.

The thickness of the PET film is 1 μ-4 μ
Is preferred. If it is less than 1 μm, the manufacturing cost is high, and the strength is weak, which is not practical. Moreover, when it is 4μ or more, the rating is 1m.
A general thermal head 7 having a J / dot level is too thick to punch.

The porous support 25 of the present embodiment is mainly composed of natural fibers such as Manila hemp, Kozo, Mitsumata, synthetic fibers such as polyethylene terephthalate, polyvinyl alcohol and polyacrylonitrile, and semi-synthetic fibers such as rayon. Porous tissue is used. The base paper 1 configured as described above is wound so that the surface of the thermoplastic film 21 faces outward in FIG.

Further, as shown in FIG. 5, the thermal head 7 is provided on the alumina substrate 50 in order to improve the adhesion with the base paper 1.
The convex glaze layer 51 is provided, and the heating resistor layer 52 is provided thereon.
And conductors 53a and 53b are arranged, and an antioxidant film 54 and a protective film 55 are further covered thereover to form a shape. The heat generating portion 56 is a portion that transfers heat to the base paper 1.

Next, the operation will be described with reference to FIGS.

As shown in FIG. 3, the platen 9 is rotationally driven in the direction of arrow A by a driving device (not shown), and the base paper 1 is pulled out from the original roll 3 by the frictional force between the platen 9 and the base paper 1 and the thermal head. 7 is conveyed to a position opposite to 7.

The thermal head 7 selectively heats and melts the surface of the thermoplastic film 21 of the base paper 1 in accordance with the image information synchronized with the rotation of the platen 9 to thereby melt the base paper 1.
A perforated image is formed on the plate to make a plate.

The base paper 1 on which the punched image is formed is conveyed until the punched image area is brought into close contact with the ink application surface of the ink pad 32. In this manner, with the punched image area of the base paper 1 in close contact with the ink application surface of the ink pad 32,
By pressing the printing paper 33 so that the surface of the thermoplastic film 21 of the base paper 1 faces, the ink pad 3
The ink impregnated from the ink layer 27 in the inside 2 exudes from the perforated portion through the porous support 25 of the base paper 1, and the ink is transferred to the printing paper 33 to form an image corresponding to the perforated image.

Further, the plate-made base paper 1 is wound up by the winding-up torque of the winding-up roll 5 urged in the direction of arrow B. This winding torque is applied to the winding roll 5 by a well-known sliding device (not shown).

This sliding device is composed of a rotary drive unit to which a driving force is transmitted from the driving device of the platen 9 and a clutch for transmitting the rotation by friction torque.
In the slip device thus constructed, the peripheral speed of the winding roll 5 is always set to be higher than the peripheral speed of the platen 9 when there is no slip of the clutch.
Further, the friction torque of the clutch is set so that the tangential force of the winding roll 5 is smaller than the friction force between the base paper 1 and the platen 9. Therefore, the clutch slips by the difference between the peripheral speed of the take-up roll 5 and the peripheral speed of the platen 9, and the friction torque of the clutch, that is, the take-up torque is applied to the take-up roll 5.

FIG. 6 is a block diagram showing the electrical construction of this embodiment. The configuration and the operation of the control unit are substantially the same as those described in the specification and drawings of Japanese Patent Application No. 3-63283 previously filed by the applicant of the present application, and therefore detailed description thereof will be omitted. The keyboard 102 is configured to send a signal to the CPU 101 by selecting a desired character and pressing a punch key. The CPU 101 corresponds to a control unit and is configured to operate according to a flowchart described later. The driver 105 is configured to turn on each dot of the thermal head 7 according to a signal supplied from the CPU 101. The drive power supply 106 is configured to supply the driver 105 with the power necessary to turn on each dot of the thermal head 7, and the maximum supply power of the drive power supply 64 causes 64 of the total number of dots of the thermal head 7 to be supplied.
Dots can be turned on at the same time. The thermal head 7 constitutes a line head unit together with the driver 105, and is configured to punch the base paper 1 according to a signal supplied from the driver 105. Further, the CPU 101 is connected to a storage device 103 that stores character patterns and the like, and a transport device 104 that transports the base paper 1.

When the punch key is pressed on the keyboard 102, the character pattern data is read from the storage device 103. Next, the base paper 1 is transported by driving the transport device 104. Then, the thermal head 7 punches a character pattern on the base paper 1.

First, the power is turned on. Next, when a desired character is input from the keyboard 102, the corresponding character code is sent to the CPU 101. And the storage means 103
The character pattern corresponding to the character code is called from.

FIG. 7 shows a character pattern in which one line 12 * 64 = 768 dots is divided into 12 blocks. The feed direction is from left to right. Here, the maximum power source is 6
4 dots can be turned on at the same time.

When the punch key is pressed on the keyboard 102, C
A signal is sent to the PU 101, and the initial setting is executed (S1 in FIG. 8). This initialization is performed every time the columns are changed. In FIG. 7, when the number of dots in the block on the column A is sequentially counted from the block a (S2), there is no dot to be turned on (S3), and the process moves to the next block b (S1).
6). If there is a dot to be turned on, the block number is stored. After the above processing is performed for one line, there is no block number stored, so that it is not turned on.

If the number of dots in the block a is counted on the column B, the counter is 64 or less (S4).
The block number a is stored (S5). When the counting is continued, the block numbers a to m will be stored when one line is completed. Since there are stored blocks (S17), blocks a to m are simultaneously turned on (S17). In this case, the block is turned on once at a time.

In the case of column C, the number of dots in the block is counted in order from block a. Similar to column A,
There is no dot to turn on, so do not turn on the block.

On the column D, when the number of dots in the block is counted in order from the block a, the block f is first obtained.
The counter exceeds 64 at. By this time, block numbers a to e have been stored, so blocks a to e
Are simultaneously turned on (S11). The block number stored here is cleared (S12), and the current block number f is newly stored (S13). 64 from the counter
(S14) When the counting is restarted from the next block, the counter exceeds 64 in block i. Since the block numbers f to h have been stored by this time, the blocks f to h are simultaneously turned on (S11). Here, the block number stored again is cleared (S1
2) The i of the current block number is newly stored (S1
3). When 64 is subtracted from the counter (S14) and counting is restarted from the next block, counting for one line is finished before the counter reaches 64. Since the block numbers i to m have been stored by this time (S17), the blocks i to m are simultaneously turned on (S18). In this case, the blocks are simultaneously turned on three times.

If the counter is exactly 64, (S
6) The current block number is stored (S7), and the block having the block number stored up to this point is turned on (S8). The block number stored here is cleared (S9), and the counter is reset to 0 (S10).

As described above, control is performed so that the number of dots that are turned on at the same time sequentially from the block a is 64 dots or less. This enables control with a power supply that can simultaneously turn on up to 64 dots. Further, when the number of dots to be turned on in each block is small, since a plurality of blocks are turned on at the same time, the number of times of turning on is smaller than that of turning on for each block as in the conventional example, so that the printing speed is not extremely lowered. It becomes possible to control.

As described above, the present invention is not limited to the embodiments as described above, and can be carried out in various modes without departing from the scope of the present invention.

For example, a dot printer or an inkjet printer may be used.

[0034]

As is clear from the above description,
According to the line printer of the present invention, it is possible to drive with a small-capacity drive power source, and the printing speed does not drop extremely.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a perspective view of a printer according to an embodiment of the present invention.

FIG. 3 is a sectional view of a printer according to an embodiment of the present invention.

FIG. 4 is a sectional view of a heat-sensitive stencil sheet according to an embodiment of the present invention.

FIG. 5 is a sectional view of a thermal head according to an embodiment of the present invention.

FIG. 6 is a block diagram showing an electrical configuration of an embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a character pattern according to an embodiment of the present invention.

FIG. 8 is a flowchart of a control program according to an embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a conventional character pattern.

[Explanation of symbols]

 7 Thermal head 101 CPU 105 Driver 106 Drive power supply

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location 9113-2C B41J 3/20 114 B

Claims (1)

[Claims] 1. A line head unit for forming an image on a print medium, and a drive power source capable of supplying electric power enough to turn on a number of dots smaller than the total number of dots of one line of the line head unit. The number of dots that are turned on within one line of the line head means is counted, and when the counted number becomes larger than a predetermined value determined according to the maximum power that can be supplied by the driving power source, A line printer having a control means for turning on a number of dots or less.